Six Causes of Engine Knock
It’s important to determine the cause of a knocking engine because the engine may be damaged. All you need to do is bring your vehicle to Righteous Auto Care. We will inspect the engine to determine the reason why it is making knocking noises. The problem could be a detonation problem or an issue with the cylinder block. The latter is the problem that can damage the engine.
1. Low-Octane Fuel
If you drive a sports car but put fuel with an octane rating of 87 in the tank, the engine is going to knock. High-performance engines require fuel with higher octane ratings because they need the fuel to burn faster. Slow-burning fuel will detonate multiple times in each cylinder and make a knocking noise.
2. Faulty Sensor
You may also have a malfunctioning sensor that is indirectly causing the knocking noises. The engine has a knock sensor that alerts the engine control module if the engine is making a knocking sound. If the sensor dies, the module may be unaware that the engine is knocking and fail to resolve the problem.
3. Lean Fuel Mixture
For example, if you have a faulty knock sensor in the engine and a fuel mixture that is lean, the module will fail to add fuel to the chamber to balance out the air and fuel and stop the knocking. Any time there is excess air in the fuel mixture, the cylinders will produce multiple detonations.
4. Worn Spark Plugs
Multiple detonations in the cylinders can also be caused by worn spark plugs. Once we replace the plugs, the knocking noise should stop. In addition to being worn out, the spark plugs can also misfire if the engine control module is malfunctioning and firing them at the wrong time.
5. Loose Rod Bearings
Worn rod bearings can damage your engine. When the bearings wear out, the rods are no longer able to move the pistons up and down inside the cylinders without making contact with the cylinder walls. Unfortunately, the pistons can damage the cylinder walls as they crash against them.
6. Loose Accessory Belt
Finally, you may think your engine is knocking if the accessory belt is loose. Rather than the engine knocking, the belt is actually slapping against other auto parts and causing the noise that is coming from the engine. We can tighten the belt or replace the tensioner if necessary.
Call Righteous Auto Care in Racine, WI, today to set up a service visit for your automobile if the engine is knocking.